NAME¶

std::ranges::adjacent_view::begin - std::ranges::adjacent_view::begin

Synopsis¶

constexpr auto begin() requires (!__SimpleView<V>); (1) (since C++23)
constexpr auto begin() const requires ranges::range<const V>; (2) (since C++23)

Returns an iterator to the first element of the adjacent_view.

Let base_ be the underlying view.

1) Equivalent to return /*iterator*/<false>(ranges::begin(base_),
ranges::end(base_));.
2) Equivalent to return /*iterator*/<true>(ranges::begin(base_),
ranges::end(base_));.

Parameters¶

(none)

Return value¶

Iterator to the first element.

Example¶

// Run this code

#include <ranges>
#include <tuple>
#include <type_traits>

int main()
{
constexpr static auto v = {'A', 'B', 'C', 'D', 'E'};

constexpr auto view = std::views::adjacent<3>(v);

constexpr auto tuple = *view.begin();

static_assert
(
std::is_same_v
<
decltype(tuple),
const std::tuple<char const&, char const&, char const&>
>
);

static_assert
(
std::get<0>(tuple) == 'A' &&
std::get<1>(tuple) == 'B' &&
std::get<2>(tuple) == 'C'
);
}

See also¶

end returns an iterator or a sentinel to the end
(C++23) (public member function)
ranges::begin returns an iterator to the beginning of a range
(C++20) (customization point object)